Glass capillary optics, recently introduced by Kumakhov and coworkers in Russia, make use of the nearly total external reflection of x-rays at grazing incidence to provide a means for focusing and transporting x-rays in a manner analogous to conventional fiber optics. Focused arrays of these optics have two properties which may be particularly useful in connection with scatter reduction and enhancement of spatial resolution; 1. The angular acceptance of the individual capillaries is on the order of a milliradian. Therefore it should be possible to place them in front of an image receptor to provide nearly complete rejection of scattered radiation. 2. The diverging point spread function associated with an extended focal spot is intercepted by the capillaries and transported to the image receptor in such a way that the effective blurring is limited to that which is present at the input to the capillary array. This should permit radiographic imaging at arbitrarily large magnifications without incurring the usual degradation of spatial resolution due to the growth of the effective focal spot size. This will enhance the effective resolution of available detectors such as photostimulable phosphor plates. The overall goals of this application are to investigate the feasibility of using diverging glass capillary optics for digital mammography and dual energy chest radiography. The first project will examine both of the above potential advantages in an energy range where significant experimental data already exists, while the second will investigate the possible extension of the scatter rejection technique to chest radiography. In each of these studies we intend to develop an optimal design for these applications and to conduct feasibility measurements of the x-ray imaging properties of the capillary devices in prototype devices. Should feasibility be demonstrated, it is our intention to develop proposals for clinical evaluation of the mammographic scanning system and further investigation of a clinically useable chest radiography system.